Field of the Invention
The disclosure relates generally to a dimmable instant-start ballast, and more particularly it relates to a dimmable instant-start ballast with a wide dimming range.
Description of the Related Art
Nowadays, most dimmable instant-start ballasts for fluorescent lamps cannot dim the fluorescent lamps under 50%. The main cause is that the temperature of the fluorescent lamps would not be high enough for the fluorescent lamps to remain in normal operation. A quick solution for this problem is to provide additional preheating energy for the fluorescent lamp. Therefore, most of the dimmable ballasts that are available nowadays are the rapid-start type, or are a programmed-start type for deep dimming.
In addition, since a fluorescent lamp is able to be directly replaced by an LED lamp nowadays, as LED lamps are advantageous in terms of saving power compared to the fluorescent lamps, an instant-start ballast for deep dimming which is able to simultaneously drive LED lamps and fluorescent lamps is required.